Battery heating circuits and methods based on battery discharging and charging using resonance components in series and multiple charge storage components

ABSTRACT

Under one aspect, a heating circuit for a battery includes a plurality of switch units, a switching control module, a damping component, an energy storage circuit, and a polarity inversion unit. The energy storage circuit is connected with the battery, and includes a current storage component and a plurality of charge storage components that respectively are connected with the plurality of switch units in series to form a plurality of branches that are connected in parallel with each other and in series with the current storage and damping components. The switching control module controls switching on and off of the switch units, so that energy flows back-and-forth between the battery and the energy storage circuit when the switch units switch on. The polarity inversion unit is connected with the energy storage circuit inverts a voltage polarity of the plurality of charge storage components after the switch units switch off.

1. CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No.201010245288.0, filed Jul. 30, 2010, Chinese Patent Application No.201010274785.3, filed Aug. 30, 2010, and Chinese Patent Application No.201110081276.3, filed Mar. 31, 2011, all these three applications beingincorporated by reference herein for all purposes.

Additionally, this application is related to International ApplicationPublication No. WO2010/145439A1 and Chinese Application Publication No.CN102055042A, both these two applications being incorporated byreference herein for all purposes.

2. BACKGROUND OF THE INVENTION

The present invention pertains to electric and electronic field, inparticular related to a battery heating circuit.

Considering cars need to run under complex road conditions andenvironmental conditions or some electronic devices are used under harshenvironmental conditions, the battery, which serves as the power supplyunit for electric-motor cars or electronic devices, need to be adaptiveto these complex conditions. In addition, besides these conditions, theservice life and charge/discharge cycle performance of the battery needto be taken into consideration; especially, when electric-motor cars orelectronic devices are used in low temperature environments, the batteryneeds to have outstanding low-temperature charge/discharge performanceand higher input/output power performance.

Usually, under low temperature conditions, the resistance of the batterywill increase, and so will the polarization; therefore, the capacity ofthe battery will be reduced.

To keep the capacity of the battery and improve the charge/dischargeperformance of the battery under low temperature conditions, someembodiments of the present invention provide a battery heating circuit.

3. BRIEF SUMMARY OF THE INVENTION

The objective of certain embodiments of the present invention is toprovide a battery heating circuit, in order to solve the problem ofdecreased capacity of the battery caused by increased resistance andpolarization of the battery under low temperature conditions.

One embodiment of the present invention provides a battery heatingcircuit, comprising a plurality of switch units, a switching controlmodule, a damping component R1, an energy storage circuit, and apolarity inversion unit, wherein: the energy storage circuit isconnected with the battery, and comprises a current storage component L1and a plurality of charge storage components C1; the plurality of chargestorage components C1 are connected with the plurality of switch unitsin series in one-to-one correspondence to form a plurality of branches;the plurality of branches are connected in parallel with each other andthen connected with the current storage component L1 and dampingcomponent R1 in series; the switching control module is connected withthe switch units, and is configured to control ON/OFF of the switchunits, so that the energy flows back-and-forth between the battery andthe energy storage circuit when the switch units switch on; the polarityinversion unit is connected with the energy storage circuit, and isconfigured to invert the voltage polarity of the plurality of chargestorage components C1 after the switch units switch from ON state to OFFstate.

Other characteristics and advantages of the present invention will befurther described in detail in the following section for embodiments.

4. BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, as a part of this description, are providedhere to facilitate further understanding of the present invention, andare used in conjunction with the following embodiments to explain thepresent invention, but shall not be comprehended as constituting anylimitation on the present invention. In the figures:

FIG. 1 is a schematic diagram of the battery heating circuit provided inone embodiment of the present invention;

FIG. 2 is a schematic diagram of one embodiment of the switch unit shownin FIG. 1;

FIG. 3 is a schematic diagram of one embodiment of the switch unit shownin FIG. 1;

FIG. 4 is a schematic diagram of one embodiment of the switch unit shownin FIG. 1;

FIG. 5 is a schematic diagram of one embodiment of the switch unit shownin FIG. 1;

FIG. 6 is a schematic diagram of one embodiment of the switch unit shownin FIG. 1;

FIG. 7 is a schematic diagram of one embodiment of the switch unit shownin FIG. 1;

FIG. 8 is a schematic diagram of one embodiment of the polarityinversion unit shown in FIG. 1;

FIG. 9 is a schematic diagram of one embodiment of the polarityinversion unit shown in FIG. 1;

FIG. 10 is a schematic diagram of one embodiment of the one-way switchshown in FIG. 8 and FIG. 9;

FIG. 11 is a schematic diagram of one embodiment of the battery heatingcircuit provided in the present invention;

FIG. 12 shows the wave pattern corresponding to the battery heatingcircuit shown in FIG. 11;

FIG. 13 is a schematic diagram of another embodiment of the batteryheating circuit provided in the present invention;

FIG. 14 is a schematic diagram of another embodiment of the batteryheating circuit provided in the present invention.

5. DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the present invention are described in detailbelow, with reference to the accompanying drawings. It should beappreciated that the embodiments described here are only provided todescribe and explain the present invention, but shall not be deemed asconstituting any limitation on the present invention.

It is noted that, unless otherwise specified, when mentioned hereafterin this description, the term “switching control module” may refer toany controller that can output control commands (e.g., pulse waveforms)under preset conditions or at preset times and thereby control theswitch unit connected to it to switch on or switch off accordingly,according to some embodiments. For example, the switching control modulecan be a PLC. Unless otherwise specified, when mentioned hereafter inthis description, the term “switch” may refer to a switch that enablesON/OFF control by using electrical signals or enables ON/OFF control onthe basis of the characteristics of the component according to certainembodiments. For example, the switch can be either a one-way switch(e.g., a switch composed of a two-way switch and a diode connected inseries, which can be conductive in one direction) or a two-way switch(e.g., a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) oran IGBT with an anti-parallel freewheeling diode). Unless otherwisespecified, when mentioned hereafter in this description, the term“two-way switch” may refer to a switch that can be conductive in twodirections, which can enable ON/OFF control by using electrical signalsor enable ON/OFF control on the basis of the characteristics of thecomponent according to some embodiments. For example, the two-way switchcan be a MOSFET or an IGBT with an anti-parallel freewheeling diode.Unless otherwise specified, when mentioned hereafter in thisdescription, the term “one-way semiconductor component” may refer to asemiconductor component that can be conductive in one direction, such asa diode, according to certain embodiments. Unless otherwise specified,when mentioned hereafter in this description, the term “charge storagecomponent” may refer to any device that can enable charge storage, suchas a capacitor, according to some embodiments. Unless otherwisespecified, when mentioned hereafter in this description, the term“current storage component” may refer to any device that can storecurrent, such as an inductor, according to certain embodiments. Unlessotherwise specified, when mentioned hereafter in this description, theterm “forward direction” may refer to the direction in which the energyflows from the battery to the energy storage circuit, and the term“reverse direction” may refer to the direction in which the energy flowsfrom the energy storage circuit to the battery, according to someembodiments. Unless otherwise specified, when mentioned hereafter inthis description, the term “battery” may comprise primary battery (e.g.,dry battery or alkaline battery, etc.) and secondary battery (e.g.,lithium-ion battery, nickel-cadmium battery, nickel-hydrogen battery, orlead-acid battery, etc.), according to certain embodiments. Unlessotherwise specified, when mentioned hereafter in this description, theterm “damping component” may refer to any device that inhibits currentflow and thereby enables energy consumption, such as a resistor, etc.,according to some embodiments. Unless otherwise specified, whenmentioned hereafter in this description, the term “main loop” may referto a loop composed of battery, damping component, switch unit and energystorage circuit connected in series according to certain embodiments.

It should be noted specially that, considering different types ofbatteries have different characteristics, in some embodiments of thepresent invention, “battery” may refer to an ideal battery that does nothave internal parasitic resistance and parasitic inductance or has verylow internal parasitic resistance and parasitic inductance, or may referto a battery pack that has internal parasitic resistance and parasiticinductance; therefore, those skilled in the art should appreciate thatif the battery is an ideal battery that does not have internal parasiticresistance and parasitic inductance or has very low internal parasiticresistance and parasitic inductance, the damping component R1 may referto a damping component external to the battery and the current storagecomponent L1 may refer to a current storage component external to thebattery; if the battery is a battery pack that has internal parasiticresistance and parasitic inductance, the damping component R1 may referto a damping component external to the battery or refer to the parasiticresistance in the battery pack, and the current storage component L1 mayrefer to a current storage component external to the battery or refer tothe parasitic inductance in the battery pack, according to certainembodiments.

To ensure the normal service life of the battery, according to someembodiments, the battery can be heated under low temperature condition,which is to say, when the heating condition is met, the heating circuitis controlled to start heating for the battery; when the heating stopcondition is met, the heating circuit is controlled to stop heating,according to certain embodiments.

In the actual application of battery, the battery heating condition andheating stop condition can be set according to the actual ambientconditions, to ensure normal charge/discharge performance of thebattery, according to some embodiments.

In order to heat up the battery E located in the low temperatureenvironment, one embodiment of the present invention provides a batteryheating circuit; as shown in FIG. 1, the battery heating circuitcomprises a plurality of switch units 1, a switching control module 100,a damping component R1, an energy storage circuit, and a polarityinversion unit 101, wherein: the energy storage circuit is connectedwith the battery, and comprises a current storage component L1 and aplurality of charge storage components C1; the plurality of chargestorage components C1 are connected with the plurality of switch units 1in series in one-to-one correspondence to form a plurality of branches;the plurality of branches are connected in parallel with each other andthen connected with the current storage component L1 and dampingcomponent R1 in series; the switching control module 100 is connectedwith the switch units 1, and is configured to control ON/OFF of theswitch units 1, so that the energy flows back-and-forth between thebattery and the energy storage circuit when the switch units 1 switchon; the polarity inversion unit 101 is connected with the energy storagecircuit, and is configured to invert the voltage polarity of theplurality of charge storage components C1 after the switch units 1switch from ON state to OFF state.

It should be noted specially that in view different types of batterieshave different characteristics, in certain embodiments of the presentinvention, if the battery E has very high internal parasitic resistanceand parasitic inductance, the damping component R1 could refers to theparasitic resistance in the battery pack; likewise, the current storagecomponent L2 could refers to the parasitic inductance in the batterypack.

The switching control module 100 can control the energy to flow from thebattery E to the charge storage components C1 at the same time or insequence, and control the energy to flow from the charge storagecomponents C1 to the battery E at the same time or in sequence, bycontrolling the switch units 1. Wherein: the control of energy flow tothe charge storage components C1 “at the same time” and energy flow backto the battery E “at the same time” can be implemented by controllingthe switch units in the plurality of branches to switch on at the sametime. The control of energy flow to the charge storage components C1 “insequence” and energy flow back to the battery E “in sequence” can beimplemented by controlling the switch units 1 in the plurality ofbranches to switch on in an appropriate sequence. For example, theplurality of switch units 1 can be controlled to switch on at differenttimes, so that energy charge/discharge can be accomplished through theplurality of branches at different times; or, the plurality of switchunits 1 can be grouped into switch unit groups, wherein: the switchunits in each switch unit group can be controlled to switch on at thesame time, while the switch unit groups can be controlled to switch onat different times; in that way, energy charge/discharge can beaccomplished through the respective branches corresponding to therespective switch unit groups at different times. Preferably, theswitching control module 100 controls the switch units 1 in a way thatthe energy can flow from the battery E to the plurality of chargestorage components C1 at the same time and flow from the charge storagecomponents C1 back to the battery E in sequence. In such one embodiment,when the current flows in forward direction, the battery E discharges;in that state, the plurality of charge storage components C1 can beconnected with the battery E at the same time, so as to increase thecurrent; when the current flows in reverse direction, the battery E ischarged; in that state, the plurality of charge storage components C1can be connected with the battery E in sequence, so as to decrease thecurrent flow through the battery E.

The switch units 1 can be implemented in a plurality of ways. Certainembodiments of the present invention do not impose any limitation to thespecific implementation of the switch units. In one embodiment of theswitch units 1, the switch units 1 are a two-way switch K3, as shown inFIG. 2. The switching control module 100 controls ON/OFF of the two-wayswitch K3; when the battery is to be heat up, the two-way switch K3 canbe controlled to switch on; if heating is to be paused or is not needed,the two-way switch K3 can be controlled to switch off.

Employing a separate two-way switch K3 to implement the switch unit 1can simplify the circuit, reduce system footprint, and facilitate theimplementation; however, to implement cut-off of reverse current, thefollowing embodiment of the switch unit 1 is further provided in thepresent invention.

Preferably, the switch unit 1 comprises a first one-way branchconfigured to enable energy flow from the battery E to the energystorage circuit, and a second one-way branch configured to enable energyflow from the energy storage circuit to the battery E; wherein: theswitching control module 100 is connected to either or both of the firstone-way branch and second one-way branch, to control ON/OFF of theconnected branches.

When the battery is to be heated, both the first one-way branch and thesecond one-way branch can be controlled to switch on; when heating is tobe paused, either or both of the first one-way branch and the secondone-way branch can be controlled to switch off; when heating is notneeded, both of the first one-way branch and the second one-way branchcan be controlled to switch off. Preferably, both of the first one-waybranch and the second one-way branch are subject to the control of theswitching control module 100; thus, energy flow cut-off in forwarddirection and reverse direction can be implemented flexibly.

In another embodiment of the switch unit 1, as shown in FIG. 3, theswitch unit 1 may comprise a two-way switch K4 and a two-way switch K5,wherein: the two-way switch K4 and the two-way switch K5 are connectedin series opposite to each other, to form the first one-way branch andthe second one-way branch; the switching control module 100 is connectedwith the two-way switch K4 and the two-way switch K5 respectively, tocontrol ON/OFF of the first one-way branch and the second one-way branchby controlling ON/OFF of the two-way switch K4 and two-way switch K5.

When the battery is to be heated, the two-way switches K4 and K5 can becontrolled to switch on; when heating is to be paused, either or both ofthe two-way switch K4 and two-way switch K5 can be controlled to switchoff; when heating is not needed, both of the two-way switch K4 andtwo-way switch K5 can be controlled to switch off. In such animplementation of switch units 1, the first one-way branch and thesecond one-way branch can be controlled separately to switch on or off,and therefore energy flow cut-off in forward direction and reversedirection in the circuit can be implemented flexibly.

In another embodiment of switch unit 1, as shown in FIG. 5, the switchunit 1 may comprise a switch K6, a one-way semiconductor component D11,and a one-way semiconductor component D12, wherein: the switch K6 andthe one-way semiconductor component D11 are connected in series witheach other to form the first one-way branch; the one-way semiconductorcomponent D12 forms the second one-way branch; the switching controlmodule 100 is connected with the switch K6, to control ON/OFF of thefirst one-way branch by controlling ON/OFF of the switch K6. In theswitch unit 1 shown in FIG. 11, when heating is needed, the switch K6can be controlled to switch on; when heating is not needed, the switchK6 can be controlled to switch off.

Though the implementation of switch unit 1 shown in FIG. 5 enablesto-and-fro energy flow along separate branches, it cannot enable energyflow cut-off function in reverse direction. The present inventionfurther puts forward another embodiment of switch unit 1; as shown inFIG. 6, the switch unit 1 can further comprise a switch K7 in the secondone-way branch, wherein: the switch K7 is connected with the one-waysemiconductor component D12 in series, the switching control module 100is also connected with the switch K7, and is configured to controlON/OFF of the second one-way branch by controlling ON/OFF of the switchK7. Thus, in the switch unit 1 shown in FIG. 6, since there are switches(i.e., switch K6 and switch K7) in both one-way branches, energy flowcut-off function in forward direction and reverse direction is enabledsimultaneously.

Preferably, the switch unit 1 can further comprise a resistor, which isconnected in series with the first one-way branch and/or the secondone-way branch and is configured to reduce the current in the heatingcircuit for the battery E and to avoid damage to the battery E resultedfrom over-current in the circuit. For example, a resistor R6 connectedin series with the two-way switch K4 and the two-way switch K5 can beadded in the switch unit 1 shown in FIG. 3, to obtain anotherimplementation of the switch unit 1, as shown in FIG. 4. FIG. 7 alsoshows one embodiment of the switch unit 1, which is obtained byconnecting respectively resistor R2 and resistor R3 in series in boththe one-way branches in the switch unit 1 shown in FIG. 6.

In the technical scheme of certain embodiments of the present invention,when the battery E is to be heated up, the switching control module 100controls the plurality of switch units 1 to switch on at the same timeor in sequence, and thereby the battery E and the energy storagecircuits are connected in series to form a loop, and the battery Echarges the charge storage components C1; when the current in the loopreaches zero in forward direction after the peak current, the chargestorage components C1 begin to discharge, and therefore the currentflows from the charge storage components C1 back to the battery E; sinceboth the current flow in forward direction and the current flow inreverse direction in the loop flow though the damping component R1, thepurpose of heating up the battery E is attained by using the heatgeneration in the damping component R1. Above charge/discharge processcan be performed cyclically. When the temperature of the battery E risesto the heating stop condition, the switching control module 100 cancontrol the switch units 1 to switch off, and thereby the heatingcircuit will stop operation.

In the heating process described above, when the current flows from theenergy storage circuit back to the battery E, the energy in the chargestorage components C1 will not flow back to the battery E completely;instead, some energy will remain in the charge storage components C1,and ultimately the voltage across the charge storage components C1 isclose or equal to the voltage of the battery, and therefore the energyflow from the battery E to the charge storage components C1 cannotcontinue anymore; that phenomenon is adverse to the cyclic operation ofthe heating circuit. Therefore, after the switch units 1 switch from ONstate to OFF state, the voltage polarity of the charge storagecomponents C1 is inverted by using a polarity inversion unit 101 in oneembodiment of the present invention; since the voltage across the chargestorage components C1 can be added serially with the voltage of thebattery E after polarity inversion, the discharging current in theheating circuit can be increased when the switch units 1 switch onagain. The switch units 1 can be controlled to switch off at any time inone or more cycles; the switch units 1 can be controlled to switch offat any time, for example, when the current flow in the circuit is inforward direction/reverse direction, and when the current flow is zeroor not zero. A specific implementation form of switch units 1 can beselected, depending on the needed cut-off strategy; if current flowcut-off in forward direction is only needed, the implementation form ofswitch units 1 shown in FIG. 2 or FIG. 5 can be selected; if currentflow cut-off in forward direction and reverse direction is needed, theswitch units with two controllable one-way branches shown in FIG. 4,FIG. 6, or FIG. 7 can be selected. Preferably, the switching controlmodule 100 is configured to control the switch units 1 to switch offwhen the current flow though the switch units 1 is zero after the switchunits 1 switch on, so as to improve the working efficiency of thecircuit. In addition, the disturbance to the entire circuit is minimalif the switch units 1 switch off when the current flow in the circuit iszero.

In one embodiment of the polarity inversion unit 101, the polarityinversion unit 101 comprises a plurality of circuits, which areconnected with the plurality of charge storage components C1 one-to-onecorrespondence, wherein: as shown in FIG. 8, each polarity inversionunit comprises a one-way switch 3 and a current storage component L2connected in series with each other; the switching control module 100 isalso connected with the one-way switches 3, and is configured to invertthe voltage polarity of the plurality of charge storage components C1 bycontrolling the one-way switches to switch on; the inversion can beperformed for the plurality of charge storage components C1 at the sametime or in sequence.

In another embodiment of the polarity inversion unit 101, as shown inFIG. 9, the polarity inversion unit 101 comprises a plurality of one-wayswitches 3 and a current storage component L2; wherein: the plurality ofone-way switches 3 are connected at one end to the plurality of chargestorage components C1 at one end in one-to-one correspondence; theplurality of one-way switches 3 are connected at the other end to oneend of the current storage component L2, and the other end of thecurrent storage component L2 is connected to the plurality of chargestorage components C1 at the other end; the switching control module 100is also connected with the one-way switches 3, and is configured toinvert the voltage polarity of the plurality of charge storagecomponents C1 at the same time or in sequence by controlling the one-wayswitches 3 to switch on. In such one embodiment, the polarity inversionprocess of the plurality charge storage components C1 can be implementedwith one current storage component L2; therefore, the number ofcomponents can be reduced; in addition, preferably, the switchingcontrol module 100 implements the voltage polarity inversion of theplurality of the charge storage components C1 in sequence by controllingthe switch-on times of the plurality of the one-way switches 3; in thatscheme, since the voltage polarity of the plurality of the chargestorage components C1 is not inverted at the same time, the size of thecurrent storage component L2 needed in the polarity inversion unit 101can be further reduced, and therefore the size and weight of the batteryheating circuit can be further reduced.

Wherein: the one-way switch 3 can be any component that can be used toaccomplish ON/OFF control of a one-way circuit. For example, the one-wayswitch 3 can be in the structure shown in FIG. 10, which is to say, theone-way switch 3 can comprise a one-way semiconductor component D1 and aswitch K2 connected in series to each other. The plurality of one-wayswitches can be implemented with a plurality of one-way semiconductorcomponents and switches connected in series; or, they can be implementedby sharing one switch, for example, a plurality of one-way semiconductorcomponents can be connected at one end to one end of the same switch inseries, the one-way semiconductor components can be connected at theother end to a plurality of charge storage components in one-to-onecorrespondence, and the other end of the switch can be connected to thecurrent storage components, so that the number of switches in theheating circuit can be decreased; or, the plurality of one-way switchescan be implemented by sharing one one-way semiconductor component, forexample, a plurality of switches can be connected at one end to one endof a one-way semiconductor component, the switches can be connected atthe other end to a plurality of charge storage components at one end,and the other end of the one-way semiconductor component can beconnected to the current storage components, so that the number ofone-way semiconductor components in the heating circuit can bedecreased. Certain embodiments of the present invention do not imposeany limitation to the specific implementation of the one-way switchesfor the polarity inversion unit 101 in the heating circuit, as long asthe implementation can accomplish the control of the polarity inversionprocess of the plurality of charge storage components.

Hereunder the working process of the embodiments of the heating circuitfor battery E will be introduced, with reference to the FIG. 11-14,wherein: FIG. 11, FIG. 13, and FIG. 14 show different embodiments of theheating circuit for battery E, and FIG. 12 shows the wave patterncorresponding to the heating circuit for battery E shown in FIG. 11. Itshould be noted: though the features and components of certainembodiments of the present invention are described specifically withreference to FIGS. 11, 13, and 14, each feature or component can be usedseparately without other features and components, or can be used incombination or not in combination with other features and components.The embodiments of the heating circuit for battery E provided in thepresent invention are not limited to those shown in FIGS. 11, 13, and14. The grid part of the wave pattern shown in FIG. 12 indicates thatdrive pulses can be applied to the switch in one or more times withinthe period, and the pulse width can be adjusted as needed.

In the heating circuit for battery E shown in FIG. 11, the switch units1 are in the form of two-way switches (i.e., two-way switch K1 a and K1b); the two-way switch K1 a is connected with a charge storage componentC1 a in series to form a first branch, and the two-way switch K1 b isconnected with a charge storage component C1 b in series to form asecond branch; both of the two branches are connected with the currentstorage component L1, damping component R1, and battery E in series. Thepolarity inversion units 101 share one current storage component L2; theone-way semiconductor component D1 a and switch K2 a as well as theone-way semiconductor component D1 b and switch K2 b form two one-wayswitches 3, respectively, and are configured to control the polarityinversion process of charge storage component C1 a and C1 b,respectively. The switching control module can control ON/OFF of K1 a,K1 b, K2 a, and K2 b. FIG. 12 shows the wave patterns of current IC1 athrough the charge storage component C1 a and the voltage VC1 a acrossthe charge storage component C1 a as well as the current IC1 b throughthe charge storage component C1 b and the voltage VC1 b across thecharge storage component C1 b; the heating circuit shown in FIG. 11 canoperate through the following procedures:

a) The switching control module 100 controls the two-way switch K1 a andK1 b to switch on, as indicated by the time period t1 in FIG. 12; thus,the battery E can discharge in forward direction through the loopcomposed of two-way switch K1 a and charge storage component C1 a andthe loop composed of two-way switch K1 b and charge storage component C1b (as indicated by the positive half cycles of current IC1 a and IC1 bin the time period t1 in FIG. 12), and can be charged in reversedirection (as indicated by the negative half cycles of current IC1 a andIC1 b in the time period t1 in FIG. 12);

b) The switching control module 100 controls the two-way switch K1 a andK1 b to switch off when the current in reverse direction is zero.

c) The switching control module 100 controls the switch K2 b to switchon, and thus the charge storage component C1 b discharges through theloop composed of one-way semiconductor component D1 b, current storagecomponent L2, and switch K2 b, and attain the purpose of voltagepolarity inversion, and then, the switching control module 100 controlsthe switch K2 b to switch off, as indicated by the time period t2 inFIG. 12;

d) The switching control module 100 controls the switch K2 a to switchon, and thus the charge storage component C1 a discharges through theloop composed of one-way semiconductor component D1 a, current storagecomponent L2, and switch K2 a, and attain the purpose of voltagepolarity inversion, and then, the switching control module 100 controlsthe switch K2 a to switch off, as indicated by the time period t3 inFIG. 12;

e) The step a) to step d) are repeated; thus, the battery E is heated upcontinuously in the charge/discharge cycles, till the battery E meetsthe heating stop condition.

In the heating circuit for battery E shown in FIG. 13, the switch units1 are still in the form of two-way switches shown in FIG. 11 (i.e.,two-way switch K1 a and K1 b); the two-way switch K1 a is connected witha charge storage component C1 a in series to form a first branch, andthe two-way switch K1 b is connected with a charge storage component C1b in series to form a second branch; both of the two branches areconnected with the current storage component L1, damping component R1,and battery E in series. The polarity inversion units 101 still shareone current storage component L2; however, different to the polarityinversion units shown in FIG. 11, the polarity inversion units in FIG.13 employ one-way semiconductor component D1 a and switch K2 a andswitch K2 b as one-way switches in them, wherein: the switch K2 a and K2b are connected at one end to one end of the one-way semiconductorcomponent D1 a, and the switch K2 a and K2 b are connected at the otherend to charge storage component C1 a and C1 b, respectively; the otherend of the one-way semiconductor component D1 a is connected to thecurrent storage component L2. The switching control module 100 cancontrol ON/OFF of K1 a, K1 b, K2 a, and K2 b, so as to control theworking process of the entire heating circuit. Compared to the heatingcircuit shown in FIG. 11, the heating circuit for battery E shown inFIG. 13 is slightly different only in the circuit structure of one-wayswitches in the polarity inversion units 101, while the operatingprocess is essentially the same. Therefore, it will not be furtherdetailed here.

In the heating circuit for battery E shown in FIG. 14, the switch units1 are still in the form of two-way switches shown in FIG. 11 (i.e.,two-way switch K1 a and K1 b); the two-way switch K1 a is connected witha charge storage component C1 a in series to form a first branch, andthe two-way switch K1 b is connected with a charge storage component C1b in series to form a second branch; both of the two branches areconnected with the current storage component L1, damping component R1,and battery E in series. The polarity inversion units 101 still shareone current storage component L2; however, different to the polarityinversion units shown in FIG. 11, the polarity inversion units in FIG.14 employ one-way semiconductor component D1 a, one-way semiconductorcomponent D1 b, and switch K2 a as one-way switches in them, wherein:the one-way semiconductor component D1 a and one-way semiconductorcomponent D1 b are connected at one end to one end of the switch K2 a,the one-way semiconductor component D1 a and one-way semiconductorcomponent D1 b are connected at the other end to the charge storagecomponent C1 a and C1 b, respectively, and the other end of the switchK2 a is connected to the current storage component L2. The switchingcontrol module 100 can control ON/OFF of K1 a, K1 b, K2 a, and K2 b, soas to control the working process of the entire heating circuit. Whenthe heating circuit shown in FIG. 14 operates, first, the two-way switchK1 a can be controlled to switch on, so that the battery E can dischargeand be charged through the branch of charge storage component C1; then,the two-way switch K1 a can be controlled to switch off, and the switchK2 a can be controlled to switch on, so as to invert the voltagepolarity of the charge storage component C1 a; after the voltagepolarity inversion of charge storage component C1 is accomplished, theswitch K2 a can be controlled to switch off; then, the two-way switch K1b can be controlled to switch on, so that the battery E can dischargedand be charged through the branch of the charge storage component C1 b;next, the two-way switch K1 b can be controlled to switch off, and theswitch K2 a can be controlled to switch on, so as to invert the voltagepolarity of the charge storage component C1 b; after the voltagepolarity inversion of charge storage component C1 b is accomplished, theswitch K2 a can be controlled to switch off. The cycles can be repeated,till the condition for stopping battery heating is met.

The heating circuit provided in certain embodiments of the presentinvention can improve the charge/discharge performance of the battery;in addition, since the energy storage circuit and switch unit areconnected with the battery in series in the heating circuit, safetyproblem related with failures and short circuit of the switch unit canbe avoided when the battery is heated owing to the existence of thecharge storage component connected in series, and therefore the batterycan be protected effectively. In addition, a polarity inversion unit isadded in the heating circuit provided in certain embodiments of thepresent invention; thus, after the switch unit switches off, thepolarity inversion unit can invert the voltage polarity of the chargestorage components in the energy storage circuit; since the voltageacross the charge storage component can be added serially with thevoltage of the battery after polarity inversion, the discharging currentin the heating circuit can be increased when the switch unit iscontrolled to switch on at the next time, and thereby the workingefficiency of the heating circuit can be improved. Moreover, inembodiments of the present invention, a single inductor is employed toimplement polarity inversion; therefore, the number of components can bereduced, and thereby the size and weight of the battery heating circuitcan be reduced.

For example, some or all components of various embodiments of thepresent invention each are, individually and/or in combination with atleast another component, implemented using one or more softwarecomponents, one or more hardware components, and/or one or morecombinations of software and hardware components. In another example,some or all components of various embodiments of the present inventioneach are, individually and/or in combination with at least anothercomponent, implemented in one or more circuits, such as one or moreanalog circuits and/or one or more digital circuits.

While some embodiments of the present invention are described above withreference to the accompanying drawings, the present invention is notlimited to the details of those embodiments. Those skilled in the artcan make modifications and variations, without departing from the spiritof the present invention. However, all these modifications andvariations shall be deemed as falling into the scope of the presentinvention.

In addition, it should be noted that the specific technical featuresdescribed in the above embodiments can be combined in any appropriateway, provided that there is no conflict. To avoid unnecessaryrepetition, certain possible combinations are not describedspecifically. Moreover, the different embodiments of the presentinvention can be combined as needed, as long as the combinations do notdeviate from the spirit of the present invention. However, suchcombinations shall also be deemed as falling into the scope of thepresent invention.

Hence, although specific embodiments of the present invention have beendescribed, it will be understood by those of skill in the art that thereare other embodiments that are equivalent to the described embodiments.Accordingly, it is to be understood that the invention is not to belimited by the specific illustrated embodiments, but only by the scopeof the appended claims.

What is claimed is:
 1. A heating circuit for a battery, comprising: aplurality of switch units, a switching control module, a dampingcomponent, an energy storage circuit, and a polarity inversion unit,wherein: the energy storage circuit is connected with the battery, andcomprises a first current storage component and a plurality of chargestorage components; the plurality of charge storage components areconnected with the plurality of switch units in series in one-to-onecorrespondence to form a plurality of branches; the plurality ofbranches are connected in parallel with each other and connected withthe first current storage component and damping component in series; theswitching control module is connected with the switch units, and isconfigured to control switching on and off of the switch units, so thatenergy flows back-and-forth between the battery and the energy storagecircuit when the switch units switch on; the polarity inversion unit isconnected with the energy storage circuit, and is configured to invert avoltage polarity of the plurality of charge storage components after theswitch units switch from on to off.
 2. The heating circuit according toclaim 1, wherein: the polarity inversion unit comprises a plurality ofinversion circuits; the plurality of inversion circuits are connectedwith the plurality of charge storage components in one-to-onecorrespondence, wherein: each inversion circuit comprises a one-wayswitch and the first current storage component connected in series witheach other; the switching control module is also connected with theone-way switches, and is configured to invert the voltage polarity ofthe plurality of charge storage components by controlling the one-wayswitches to switch on.
 3. The heating circuit according to claim 1,wherein: the polarity inversion unit comprises a plurality of one-wayswitches and a second current storage component; the plurality ofone-way switches are connected at one end to the plurality of chargestorage components at one end in one-to-one correspondence, theplurality of one-way switches are connected at the other end to one endof the second current storage component, and the other end of the secondcurrent storage component is connected to the plurality of chargestorage components at the other end; the switching control module isalso connected with the one-way switches, and is configured to invertthe voltage polarity of the plurality of charge storage components atthe same time or in sequence by controlling the one-way switches toswitch on.
 4. The heating circuit according to claim 1, wherein: eachswitch unit is a two-way switch.
 5. The heating circuit according toclaim 1, wherein: each switch unit comprises a first one-way branchconfigured to transfer energy from the battery to the energy storagecircuit and a second one-way branch configured to transfer energy fromthe energy storage circuit to the battery; the switching control moduleis connected with either or both of the first one-way branch and secondone-way branch, to control switching on and off of the connected branch.6. The heating circuit according to claim 5, wherein: each switch unitcomprises a first two-way switch and a second two-way switch, the firsttwo-way switch and the second two-way switch are connected in seriesopposite to each other to form the first one-way branch and the secondone-way branch; the switching control module is connected with the firsttwo-way switch and the second two-way switch respectively, and isconfigured to control switching on and off of the first one-way branchand the second one-way branch by controlling switching on and off of thefirst two-way switch and the second two-way switch.
 7. The heatingcircuit according to claim 5, wherein: each switch unit comprises afirst switch, a first one-way semiconductor component, and a secondone-way semiconductor component, the first switch and the first one-waysemiconductor component are connected with each other in series toconstitute the first one-way branch; the second one-way semiconductorcomponent constitutes the second one-way branch; the switching controlmodule is connected with the first switch, and is configured to controlswitching on and off of the first one-way branch by controllingswitching on and off of the first switch.
 8. The heating circuitaccording to claim 7, wherein: each switch unit further comprises asecond switch in the second one-way branch, and the second switch isconnected with the second one-way semiconductor component in series; theswitching control module is also connected with the second switch, andis configured to control switching on and off of the second one-waybranch by controlling switching on and off of the second switch.
 9. Theheating circuit according to claim 5, wherein: each switch unit furthercomprises a resistor connected in series with the first one-way branchand/or the second one-way branch.
 10. The heating circuit according toclaim 1, wherein: the switching control module controls each switch unitto switch off when or after a current through that switch unit reacheszero after that switch unit switches on.
 11. The heating circuitaccording to claim 1, wherein: the switching control module controls theplurality of switch units, so that the energy can flow from the batteryto the charge storage components at the same time or in sequence, andthe energy can flow from the charge storage components to the battery atthe same time or in sequence.
 12. The heating circuit according to claim1, wherein: the damping component is a parasitic resistance in thebattery, and the first current storage component is a parasiticinductance in the battery.